Another vote for G&L. My midnight oil G&Ls are getting quite a bit of wear. It's a perfect business casual fabric. Looks fantastic! Can't wait to pick mine up tomorrow. Curious to see about the length issue.
Short answer: probably not. Long answer: yes but only if your tailor is a wizard. They'd have to remove the wrist or take it up from the shoulder, either of which might adversely impact the waxed finish. It would be a very tough operation. I use Stanton Street Tailors, a top NYC outfit, and this is probably the kind of job Pablo, the boss, would turn down because it's too much of a headache.
Thanks! Me too! Can't wait to pick it up later this week. Curious to see Also @TweedyProf IIRC decided a month or so ago against adding darts to the Doyle. I checked and my existing chore jacket from Woolrich Woolen Mills has back darts (came with them) and it makes it wear strangely. Far too restrictive even though it "fits." You'll be glad you didn't dart the Doyle.
Walts usually already have enough fabric in the thighs and seat to let them out to a Rudy-esque fit. It won't be perfect, and stitching might show on light-colored cotton Walts, but I've had success doing this in the past. I believe Mike has as well. I let out all my linen Walts, for instance. The Walt fits me fine, but I like the extra room in a linen pant.